Acid activation of ruthenium metathesis catalysts and living ROMP metathesis polymerization in water

ABSTRACT

Activation of ruthenium based catalyst compounds with acid to improve reaction rates and yields of olefin metathesis reactions, including ROMP, RCM, ADMET and cross-methasis reactions is disclosed. The ruthenium catalyst compounds are ruthenium carbene complexes of the general formula A x L y X z Ru═CHR′ where x=0, 1 or 2, y=0, 1 or 2, and z=1 or 2 and where R′ is hydrogen or a substituted or unsubstituted alkyl or aryl, L is any neutral electron donor, X is any anionic ligand, and A is a ligand having a covalent structure connecting a neutral electron donor and an anionic ligand. The use of acid with these catalysts allows for reactions with a wide range of olefins in a variety of solvents, including acid-initiated RIM processes and living ROMP reactions of water-soluble monomers in water.

[0001] This application claims the benefit of U.S. ProvisionalApplication No. 60/064,405, filed Oct. 30, 1997, which is incorporatedherein by reference.

[0002] The U.S. Government has certain rights in this invention pursuantto Grant No. CH 9509745 awarded by the National Science Foundation andGrant No. GM 31332 awarded by the National Institutes of Health.

BACKGROUND OF THE INVENTION

[0003] 1. Field of the Invention

[0004] The invention relates to highly active and stable ruthenium metalcarbene complex compounds and their use as catalysts for olefinmetathesis reactions.

[0005] 2. Description of the Related Art

[0006] The formation of carbon-carbon bonds via olefin metathesis is ofconsiderable interest and commercial utility, and considerable researchefforts have been undertaken to develop olefin metathesis catalysts andsystems. Group VIII transition metal catalysts have proven to beparticularly useful for catalyzing olefin metathesis reactions, such asring-opening metathesis polymerization (ROMP), ring-closing metathesispolymerization (RCM), acyclic diene metathesis (ADMFT), and crossmetathesis reactions. Both classical and well-defined olefin metathesiscatalysts based on ruthenium have been shown to exhibit good toleranceto a variety of functional groups, as has been reported by, e.g.,Grubbs, R. H. J.M.S.—Pure Appl. Chem. 1994, A31(11), 1829-1833; AqueousOrganometallic Chemistry and Catalysis. Horvath, I. T., Joo, F. Eds;Kluwer Academic Publishers: Boston, 1995; Novak, B. M.; Grubbs, R. H. J.Am. Chem. Soc. 1988, 110,7542-7543; Novak, B. M.; Grubbs, R. H. J. Am.Chem. Soc. 1988, 110, 960-96; Nguyen, S. T.; Johnson, L. K.; Grubbs, R.H. J. Am. Chem. Soc. 1992, 114, 3974-3975 and Schwab, P.; Grubbs, R. H.;Ziller, J. W. J. Am. Chem. Soc. 1996, 118, 100, each of which isincorporated herein by reference. In particular, as reported by Lynn, D.M.; Kanaoka, S.; Grubbs, R. H. J. Am. Chem. Soc. 1996, 118, 784 and byMohr, B.; Lynn, D. M.; Grubbs, R. H. Organometallics 1996, 15,4317-4325, both of which are incorporated herein by reference, therobust nature of the ruthenium-carbon bonds in these complexes hasenabled olefin metathesis reactions to be carried out in protic media.However, slow reaction rates and low yields have limited the applicationof these catalysts for a variety of olefin monomers and reactionconditions.

[0007] As an example, there is a need for homogeneous polymerizationsystems that are living in water and that will polymerize water-solublemonomers. In living polymerization systems, polymerization occurswithout chain transfer or chain termination, giving greater control overpolydispersity of the resultant polymers. Such polymerization systemsare highly desirable as they would allow the controlled synthesis ofwater-soluble polymers and would enable precise control over thecomposition of block copolymers for use, for example, in biomedicalapplications. However, such polymerization systems represent aformidable challenge. For example, the addition of water to traditionalliving anionic or cationic systems results in rapid termination. Theadvent of late transition metal catalysts tolerant of numerous polar andprotic functionalities has recently enabled living ring-openingmetathesis polymerizations (ROMP), free-radical polymerizations, andisocyanide polymerizations in aqueous environments, as reported by Lynn,D. M.; Kanaoka, S.; Grubbs, R. H. J. Am. Chem. Soc. 1996, 118, 784;Manning, D. D.; Strong, L. E.; Hu, X.; Beck, P.; Kiessling, L. L.Tetrahedron, 1997, 53, 11937-11952; Manning, D. D.; Hu, X.; Beck, P.;Kiessling, L. L. J.Am. Chem. Soc. 1997, 119, 3161-3162; Nishikawa, T;Ando, T; Kamigaito, M; Sawamoto, M. Macromolecules 1997, 30, 2244-2248;Deming, T. J.; Novak, B. M. Polym. Prepr. (Am. Chem. Soc., Div. Polym.Chem.) 1991, 32, 455-456; and Deming, T. J.; Novak, B. M.Macromolecules, 1991, 24, 326-328, each of which is incorporated hereinby reference. Although these examples represent significant advancestoward entirely aqueous systems, the catalysts themselves are insolublein water and the polymerization reactions basically occur in “wet”organic phases.

[0008] Aqueous ring-opening metathesis polymerization of strained,cyclic olefins initiated by Group VIII salts and coordination complexesis well-documented. Although these complexes serve as robustpolymerization catalysts in water, the polymerizations are not livingand inefficient initiation steps produce erratic results (typically lessthan 1% of metal centers are converted to catalytically-active species)and results in poor control over polymer molecular weight.

[0009] We recently reported the synthesis of well-defined, water solubleruthenium alkylidenes which serve as excellent initiators for olefinmetathesis reactions in water, methanol, and aqueous emulsions. SeeMohr, B.; Lynn, D. M.; Grubbs, R. H. Organometallics, 1996, 15,4317-4325, incorporated herein by reference. Further investigation ofthese complexes, however, revealed that potential applications could belimited by relatively fast termination reactions. Similar rutheniumalkylidene complexes are disclosed in U.S. Pat. Nos. 5,312,940 and5,342,909 and U.S. application Ser. No. 08/693,789, filed Jul. 31, 1996,and Ser. No. 08/708,057, filed Aug. 30, 1996, each of which isincorporated herein by reference.

[0010] For these reasons, there is a need for well-defined olefinmetathesis catalysts and systems with improved efficiencies that providefor increased reaction rates, increased product yields, and that allowfor metathesis of a wider range of olefins in a broader range ofsolvents than previously possible.

SUMMARY OF THE INVENTION

[0011] The present invention meets the above and other needs and isdirected to the use of acid to activate and enhance ruthenium-basedmetathesis catalysts for olefin metathesis, including ring-openingmetathesis polymerization (ROMP) of strained and unstrained cyclicolefins, and ring-closing metathesis (RCM), acyclic diene metathesis(ADMET), and cross metathesis reactions of acyclic olefins.

[0012] In one embodiment of the invention, the ruthenium catalystcompounds are ruthenium carbene complexes of the general formulaA_(x)L_(y)X_(z)Ru═CHR′ where x=0, 1 or 2, y=0, 1 or 2, and z=1 or 2, andwhere R′ is hydrogen or a substituted or unsubstituted alkyl or aryl, Lis any neutral electron donor, X is any anionic ligand, and A is aligand having a covalent structure connecting a neutral electron donorand an anionic ligand. In other embodiments of the invention, theruthenium catalyst compounds have the general formulas: A₂LRu═CHR′,ALXRu═CHR′ and L₂X₂Ru═CHR′.

[0013] These ruthenium catalysts contain acid-labile ligands and theaddition of inorganic or organic acids to olefin metathesis reactionsemploying these catalysts results in substantially enhanced activitiesrelative to systems in which acid is not present. Substantial rateincreases in the presence of acid have been observed for olefinmetathesis reactions in aqueous, protic and organic solvents in methodsaccording to the present invention.

[0014] In another aspect of the invention, acid is used to activateruthenium alkylidene complexes that are otherwise unreactive witholefins. This aspect of the invention allows for greater control inreaction injection molding (RIM) processes, as the catalyst and monomercan be stored together, either in solution or in neat monomer, and thenacid is added to initiate polymerization. Similar processes can beapplied to photoinitiated-ROMP (PROMP) systems and to photomaskingapplications using photoacid generators (photoacid generators arecompounds that are not themselves acids, but which break down into acidsand other products upon exposure to light energy).

[0015] The invention is further directed to living polymerizationreactions taking place in aqueous solutions in the absence of anysurfactants or organic cosolvents. In another embodiment of theinvention, water-soluble ruthenium alkylidene complexes initiate livingROMP of water-soluble monomers in the presence of acid.

DETAILED DESCRIPTION OF THE INVENTION

[0016] In general, transition metal alkylidenes are deactivated ordestroyed in polar, protic species. The ruthenium alkylidenes of thepresent invention are not only stable in the presence of polar or proticfunctional groups or solvents, but the catalytic activities of thesealkylidenes are are enhanced by the deliberate addition of specificamounts of acid not present as a substrate or solvent. A number ofruthenium alkylidenes of the present invention are otherwise inactiveabsent the addition of acid to the reaction mixture. Such acidicconditions would destroy alkylidenes based on earlier transition metals.

[0017] Ruthenium alkylidenes of the present invention includealkylidenes of the general formula A_(x)L_(y)X_(z)Ru═CHR′ where x=0, 1or 2, y=0, 1 or 2, and z=1 or 2, and where R′ is hydrogen or asubstituted or unsubstituted alkyl or aryl, L is any neutral electrondonor, X is any anionic ligand, and A is a ligand having a covalentstructure connecting a neutral electron donor and an anionic ligand.These alkylidenes have enhanced catalytic activities in the presence ofacid for a variety of olefin metathesis reactions, including but notlimited to ROMP, RCM, ADMET and cross-metathesis and dimerizationreactions. Preferred ruthenium alkylidenes are of the general formulasA₂LRu═CHR′, ALXRu═CHR′ and L₂X₂Ru═CHR′.

[0018] Olefin monomers that can be reacted according to the processes ofthe present invention include acyclic olefins, cyclic olefins, bothstrained and unstrained, dienes and unsaturated polymers. These olefinscan be functionalized as well, and can include functional groups eitheras substituents of the olefins or incorporated into the carbon chain ofthe olefin. These functional groups can be, for example, alcohol, thiol,ketone, aldehyde, ester, disulfide, carbonate, imine, carboxyl, amine,amide, nitro acid, carboxylic acid. isocyanate, carbodiimide, ether,halogen, quaternary amine, carbohydrate, phosphate, sulfate or sulfonategroups.

[0019] Both organic and inorganic acids are useful in enhancingcatalytic activity of our catalysts, the preferred acids being HI, HCl,HBr, H₂SO₄, H₃O⁺, HNO₃, H₃PO₄, CH₃CO₂H and tosic acid, most preferablyHCl. Acids may be added to the catalysts either before or during thereaction with olefin, with longer catalyst life generally observed whenthe catalyst is introduced to an acidic solution of olefin monomer. Theacid or the catalyst can be dissolved in a variety of suitable solvents,including protic, aqueous or organic solvents or mixtures thereof.Preferred solvents include aromatic or halogenated aromatic solvents,aliphatic or halogenated organic solvents, alcoholic solvents, water ormixtures thereof. Of the aromatic solvents, the most preferred isbenzene. Dichloromethane is most preferred of the halogenated aliphaticsolvents; methanol is most preferred of the alcoholic solvents.Alternatively, the acid or the catalyst or both can be dissolved intoneat olefin monomer.

[0020] In addition to the above acids, an alternative embodiment of theinvention, photoacid generators that are converted to acids uponexposure to light energy may be used to activate or enhance thereaction. For example, UV curing of dicyclopentadiene (DCPD) to yieldpoly(DCPD) by photoinitiated-ROMP (PROMP) is readily accomplished asphotoacid generators may be stored with both monomer and catalyst untilmetathesis is initiated through irradiation.

[0021] The preferred substituents of catalysts of the present inventionare as follows. The neutral electron donor L is preferably a phosphineof the formula PR³R⁴R⁵ where R³ can be a secondary alkyl or cycloalkyl,and R⁴ and R⁵ can be an aryl, C₁-C₁₀ primary alkyl, secondary alkyl, orcycloalkyl, each independent of the other. More preferably, L is eitherP(cyclohexyl)₃, P(cyclopentyl)₃, P(isopropyl)3, or P(phenyl)₃. Theanionic ligand X is preferably hydrogen, or a halogen, or aunsubstituted or substitued moiety where the moiety is a C₁-C₂O alkyl,aryl, C₁-C₂₀ alkoxide, aryloxide, C₃-C₂₀ alkyldiketonate,aryldiketonate, C₁-C₂₀ carboxylate, arylsulfonate, C₁-C₂₀alkylsulfonate, C₁-C₂₀ alkylthio, C₁-C₂₀ alkylsulfonyl, or C₁-C₂₀alkylsulfinyl. In the case of substituted moiety, the substitution isC₁-C₅ alkyl, halogen, C₁-C₅ alkoxy, unmodified phenyl, halogensubstituted phenyl, C₁-C₅ alkyl substituted phenyl, or C₁-C₅ alkoxysubstituted phenyl.

[0022] A first preferred embodiment of the catalyst has the formula:

[0023] where each R is an aryl or alkyl, substituted or unsubstituted,and is preferably either a C₁-C₂₀ alkyl, an aryl, a substituted C₁-C₂₀alkyl (substituted with an aryl, halide, hydroxy, C₁-C₂₀ alkoxy, orC₂-C₂₀ alkoxycarbonyl) or a substituted aryl (substituted with a C₁-C₂₀alkyl, aryl, hydroxyl, C₁-C₅ alkoxy, amino, nitro, halide or methoxy).In the most preferred form, R is methyl or t-butyl, PR₃ isP(cyclohexyl)₃ and R′ is phenyl.

[0024] A second preferred embodiment of the catalyst has the formula:

[0025] where R″ is hydrogen, alkyl, halo, nitro or alkoxy, X is Cl, Br,I, CH₃CO₂ or CF₃CO₂ and each R is a substituted or unsubstituted alkylor aryl, preferably either a C₁-C₂₀ alkyl, an aryl, a substituted C₁-C₂₀alkyl (substituted with an aryl, halide, hydroxy, C₁-C₂₀ alkoxy, orC₂-C₂₀ alkoxycarbonyl) or a substituted aryl (substituted with a C₁-C₂₀alkyl, aryl, hydroxyl, C₁-C₅ alkoxy, amino, nitro, halide or methoxy).In the most preferred form, R′ is phenyl, R″ is nitro, PR₃ isP(cyclohexyl)₃, X is Cl and R is aryl or aryl substituted with2,6-diisopropyl groups.

[0026] A third preferred embodiment of the catalyst has the formula:

[0027] where PR₃ is either P(cyclohexyl)₃, P(cyclopentyl)₃,P(isopropyl)₃, or P(phenyl)₃ and X is Cl, Br, I, CH₃CO₂ or CF₃CO₂.

[0028] A fourth preferred embodiment of the catalyst has the formula:

[0029] where Cy is cyclohexyl, X is Cl, Br, I, CH₃CO₂ or CF₃CO₂, and Ris one of the following:

[0030] Preferred forms of this fourth embodiment have the followingformulas:

[0031] The catalysts of this fourth embodiment are highly effective whenused in either aqueous or alcoholic solvents.

[0032] The ruthenium alkylidene compounds of the present invention maybe synthesized using diazo compounds, by neutral electron donor ligandexchange, by cross metathesis, using acteylene, using cumulated olefins,and in a one-pot method using diazo compounds and neutral electrondonors according to methods described in U.S. Pat. Nos. 5,312,940 and5,342,909 and U.S. application Ser. No. 08/693,789, filed Jul. 31, 1996,and Ser. No. 08/708,057, filed Aug. 30, 1996, and in Chang, S., Jones,L., II, Wang, C., Henling, L. M., and Grubbs, R. H., Organometallics,1998, 17, 3460-3465, Schwab, P., Grubbs, R. H., Ziller, J. W., J. Am.Chem. Soc. 1996, 118, 100-110, and Mohr, B., Lynn, D. M. and Grubbs, R.H., Organometallics, 1996, 15, 4317-4325, each of which is incorporatedherein by reference in its entirety, and to methods further describedherein.

[0033] The following non-limiting examples further illustrate thepresent invention:

EXAMPLE 1

[0034] Synthesis of Ruthenium Alkylidenes:

[0035] General Considerations.

[0036] All manipulations and reactions involving ruthenium alkylideneswere performed in a nitrogen-filled drybox or by using standard Schlenktechniques under an atmosphere of argon.

[0037] Synthesis of RuCl₂(═CH—CH═CPh₂)(PPh₃)₂

[0038] Inside a dry box a solution of RuCl₂(PPh₃)₄ (6.0 g, 4.91 mmol) ina Schenk flask was reacted with 3,3-diphenylcyclopropene (954 mg, 1.0eq) in a 1:1 mixture of CH₂Cl₂/C₆H₆. The flask was capped with astopper, removed from the box, attached to a reflux condenser underargon and heated at 53° C. for 11 h. After allowing the solution to coolto room temperature, all the solvent was removed in vacuo to give a darkyellow-brown solid. Benzene (10 ml) was added to the solid andsubsequent swirling of the mixture broke the solid into a fine powder.Pentane (80 ml) was then slowly added to the mixture via cannula whilestirring vigorously. The mixture was stirred at room temperature for 1 hand allowed to settle before the supernatant was removed via cannulafiltration. This washing procedure was repeated two more times to ensurecomplete removal of all phosphine by-products. The resulting solid wasthen dried overnight to afford 4.28 g (98%) of RuCl₂(═CH—CH═CPh₂)(PPh₃)₂as a yellow powder with a slight green tint.

[0039] Synthesis of RuCl₂(═CHPh)(PR₃)₂ complexes

[0040] RuCl₂(=CHPh)(PPh₃)₂. A solution of RuCl₂(PPh₃)₃ (2.37 g, 2.47mmol) in CH₂Cl₂ (20 mL) was treated at −78° C. with a −50° C. solutionof phenyldiazomethane (584 mg, 4.94 mmol, 2.0 equiv) in CH₂Cl₂ orpentane (3 mL). A spontaneous color change from orange-brown tobrown-green and vigorous bubbling was observed. After the cooling bathwas removed, the solution was stirred for 5 min and the solution wasthen concentrated to ˜3 mL. Upon addition of pentane (20 mL), a greensolid was precipitated which was separated from the brown mother-liquidvia cannula filtration, dissolved in CH₂Cl₂ (3 mL). and reprecipitatedwith pentane. This procedure was repeated until the mother-liquid wasnearly colorless. The remaining gray-green microcrystalline solid wasdried under vacuum for several hours. Yield=1.67 g (89%).

[0041] One-Pot Synthesis of RuCl₂(═CHPh)(PCy₃)2.

[0042] A solution of RuCl₂(PPh₃)₃ (4.0 g, 4.17 mmol) in CH₂Cl₂ (40 mL)was treated at −78° C. with a −50° C. solution of phenyldiazomethane(986 mg. 8.35 mmol, 2.0 equiv) in pentane (10 mL). Upon additioi of thediazo compound, an instantaneous color change from orange-brown togreen-brown and vigorous bubbling was observed. After the reactionmixture was stirred at −70° C. to −60° C. for 5-10 min, an ice-coldsolution of tricyclohexylphosphine (2.57 g. 9.19 mmol, 2.2 equiv) inCH₂Cl₂ was added via syringe. Accompanied by a color change frombrown-green to red. The solution was allowed to warm to room temperatureand stirred for 30 min. The solution was filtered, concentrated to halfof the volume, and filtrated. Methanol (100 mL) was added to precipitatea purple microcrystalline solid, which was filtered off, washed severaltimes with acetone and methanol (10-mL portions), and dried under vacuumfor several hours. Yield=3.40 g (99%).

[0043] One-pot Synthesis of RuCl₂(=CHPh)(PCp₃)₂.

[0044] RuCl₂(═CHPh)(PCp₃)₂ is obtained was obtained by methods analogousto those used for the one-pot synthesis of RuCl₂(=CH₂(Ph)(PCy₃)₂, as apurple microcrystalline solid, using RuCl₂(PPh₃)₃ (4.00 g, 4.17 mmol),phenyldiazomethane (986 mg, 8.35 mmol, 2.0 eq.), andtricyclopentyl-phosphine (2.19 g, 9.18 mmol, 2.2 eq.). Due to the bettersolubility of the compound, methanol was used for the washings. Yield2.83 g (92%). ¹H NMR (CD₂Cl₂): δ 20.20 (s, Ru═CH),³¹P NMR (CD₂Cl₂): δ29.96 (s, PCp₃). Anal. Calcd. for C₃₇F Cl₂P₂Ru: C, 60.15; H, 8.19.Found: C, 60.39; H, 8.21.

[0045] Synthesis of (PCy₃)(R-acac)₂(CHPh)

[0046] Inside the dry box, 200 mg (0.243 mmol) of RuCl₂(═CHR)(PCy₃)₂prepared as above were weighed into a Schlenk flask and dissolved inapproximately 120 ml of C₆H₆ and 150 mg of Tl(acetyl acetonate) (0.494mmol, 2.03 eq) were added. The flask was capped with a rubber septum,removed from the dry box, and stirred for 1-2 hrs under argon on aSchlenk line, during which time the solution turned green. The solventwas removed in vacuo, and the solids were washed with hexanes (3×5 ml)to extract the product and PCy₃. The filtrate was collected via cannulafiltration in another Schlenk flask, and the solvent was removed invacuo.

[0047] Inside the dry box, the product mixture was dissolved in benzene,and 100 mg of CuCl (1.01 mmol, 4 eq) were added. The suspension wasplaced back on the Schlenk line and stirred for 2 hrs, and the solventwas removed in vacuo. The product was extracted from the CuCl.PCy₃polymer with cold hexanes (3×5 ml). The filtrate was collected viacannula filtration, and the solvent removed in vacuo, leaving a greenpowder. ¹H NMR (C₆D6): δ 19.35 (d, 1H, Ru=CH, ³JHP-12 Hz), 8.59 (d, 2H,H_(ortho), ³J_(HH)=8.0 Hz), 7.47 (t, 1H, H_(para), ³J_(HH)=7.3 Hz), 7.37(app t, 2 H, H_(meta), ³J_(HH)=8.0, 7.3 Hz), 5.58 (s, 1H), 4.76 (s, 1H), 2.18 (s, 3H), 2.12 (s, 3H), 1.80 (s, 3H), 1.67 (s, 3H), 1.20-2.00(m,33H), ³¹P(¹H) NMR: 6 38.86 (s).

[0048] Synthesis of (PCv₃)(t-Bu₂acac)₂(CHPh)

[0049] Inside the dry box, 100 mg (0.12 mmol) of RuCl₂(═CHPh)(PCy₃)₂prepared as above were weighed into a Schlenk flask and dissolved inapproximately 10 ml of C₆H₆ and 94 mg of TI (t-Bu₂-acetyl acetonate)(0.24 mmol, 2 eq) were added. The flask was capped with a rubber septum,removed from the dry box, and stirred for 2 days under argon on aSchlenk line, during which time the solution turned green. The solventwas removed in vacuo, and the solids were washed with hexanes (3×5 ml)to extract the product and PCy₃. The filtrate was collected via cannulafiltration in another Schlenk flask, and the solvent was removed invacuo.

[0050] Inside the dry box, the product mixture was dissolved in benzene,and 100 mg of CuCl (1.01 mmol, 8 eq) were added. The suspension wasplaced back on the Schlenk line and stirred for 2 hrs, and the solventwas removed in vacuo. The product was extracted from the CuCl.PCy₃polymer with cold hexanes (3×5 ml). The filtrate was collected viacannula filtration, and the solvent removed in vacuo, leaving a lightgreen powder. ¹H NMR: δ 19.04 (d, 1 H, RU═CH, ³J_(HP)=12 Hz), 8.28 (d,2H, H_(ortho), ³J_(HH)=8.0 Hz), 7.56 (T, 1H, H_(para), ³J_(HH)=8.0 Hz),7.31 (t, 2H, H_(meta), ³J_(HH)=8.0 Hz), 5.75 (s, 1H), 5.11 (s, 1H), 1.15(app s, 18H), 1.10 (s, 9H), 0.82 (s, 9 h), 1.10-2.10 (m, 33H), 31P{1H}NMR: δ 37.90 (s).

[0051] Synthesis of Schiff-base-Substituted Ru Complexes

[0052] Schiff-base substituted Ru complexes were prepared by firstcondensing salicylaldehydes with aliphatic or aromatic aminederivatives. The resulting ligands were converted to thallium salts andthen substitution reactions were performed with RuCl₂(═CHPh)(Cy₃)₂.Successful Schiff-base ligands were prepared according to the proceduresdescribed below using the following pairs salicylaldehydes and arninederivatives: salicylaldehyde and 2,6-diisopropylaniline,5-nitrosalicylaldehyde and 2,6-diisopropylaniline,5-nitrosalicylaldehyde and 2,6-dimethyl-4-methoxyaniline,5-nitrosalicylaldehyde and 4-bromo-2,C -dimethylaniline, 5-niosalicylaldehyde and 4-amino-3,5-dichlorobenzotrifluoride,3-methyl-5-nitrosalicylaldehyde and 2,6-diisopropylaniline, and5-nitrosalicylaldehyde and 2,6-diisopropyl-4-nitroaniline.

[0053] General Procedure for the Preparation of Schiff-base Ligands.

[0054] The condensation of salicylaldehydes with aliphatic or aromaticamine derivatives was carried out with stirring in ethyl alcohol at 80°C. for 2 h. Upon cooling to 0° C., a yellow solid precipitated from thereaction mixture. The solid was filtered, washed with cold ethylalcohol, and then dried in vacuo to afford the desired salicylaldimineligand in excellent yields.

[0055] General Procedure for the Preparation of Thallium Salts.

[0056] To a solution of Schiff bases in benzene or THF (10 mL) was addeddropwise a solution of thalium ethoxide in benzene or THF (5 mL) at roomtemperature. Immediately after the addition, a pale yellow solid formedand the reaction mixture was stirred for 2 h at room temperature.Filtration of the solid under a nitrogen or argon atmosphere gave thethallium salts in quantitative yields. The salts were immediately usedin the next step without further purification.

[0057] General Procedure for Preparation of Schiff-base-Substituted RuComplexes.

[0058] To a solution of RuCl₂(═CHPh)(Cy₃)₂ prepared as above in THF (5ml) was added a solution of thallium salt prepared as above in THF (5ml). The reaction mixture was stirred at room temperature for 3 h. Afterevaporation of the solvent, the residue was dissolved in a minimalamount of benzene and cooled to 0° C. The thallium chloride (byproductof the reaction) was removed via filtration. The desired complex wasthen washed with cold benzene (10 ml×3), and the filtrate wasevaporated. The solid residue was recrystallized from pentane (−70° C.)to give the Schiff-base-substituted Ru complexes in moderate to goodyields as brown solids.

[0059] Synthesis of RuCl₂(═CHPh)[Cy₂ PCH₂CH₂N(CH₃)₃ ⁺Cl]₂

[0060] RuCl₂(═CHPh)[Cy₂PCH₂CH₂N(CH₃)₃+Cl]₂ was prepared by placingdicyclohexylphosphine (19.7 g, 0.99 mol) in THF (100 mL) into a Schlenkflask equipped with a stirbar, capped with a rubber septum, and purgingwith argon. The solution was cooled to 0° C., and BH₃.THF (100 mL of a1.0 M solution in THF, 0.1 mol, 1.01 equiv) was slowly added viacannula. The colorless solution was stirred for 2 h at 0° C. and thenallowed to warm to room temperature. Evaporation of the solvent resultedin a crystalline white solid, Cy₂PH(BH₃), which was recrystallized frompentane. (Yield: 18.9 g (90%) as white needles).

[0061] The Cy₂PH(BH₃) (4 g, 18.90 mmol) was dissolved in THF (100 mL)and was placed into a Schlenk flask and purged with argon. The solutionwas cooled to −78° C., and n-butyllithium (12.4 mL of a 1.6 M solutionin hexane, 19.80 mmol, 1.05 equiv) was added dropwise via syringe over aperiod of 10 min. The colorless reaction mixture was stirred for 2 hwhile slowly warming to room temperature. Upon cooling of the solutionto −78° C., 2-chloro-N,N-dimethylaminoethane (2.44 g, 22.70 mmol, 1.20equiv) in THF (50 mL) was slowly added via syringe. The reaction mixturewas kept for 2 h at −78° C. and then stirred at room temperatureovernight. Evaporation of the solvent gave a white solid which wassubjected to column chromatography (silica gel/methanol, R₁=0.25) toyield 3.48 g (65%) of Cy₂P(BH₃)CH₂CH₂N(CH₃)₂, as a white solid.

[0062] 1.50 g (5.30 mmol) of Cy₂P(BH₃)CH₂CH₂N(CH₃)₂ was dissolved inether (60 mL) followed by addition of methyl iodide (1.88 g, 13.24 mmol,2.5 equiv). The reaction mixture was stirred for 4 h at roomtemperature, during which a white solid precipitated. The precipitatewas collected by filtration, washed with ether and dried in vacuo toyield 2.17 g (97%) of Cy₂P(BH₃)CH₂CH₂N(CH₃)₃ ⁺I, as a white solid.

[0063] The Cy₂P(BH₃)CH₂CH₂N(CH₃)₃ ⁺I, (1.50 g, 3.53 mmol) was thendissolved in morpholine (30 mL), placed into a Schlenk flask and purgedwith argon. The reaction mixture was stirred for 2 h at 1 10° C. andthen cooled to room temperature. Evaporation of the solvent gave a gummywhite residue which was dissolved in a small mount of methanol (3 mL)and reprecipitated by addition of cold THF (25 mL). The supernatant wasremoved via cannula filtration, and the precipitate was washed with asmall amount of THF (5 m) and dried in vacuo to yield 1.05 g (72%) ofCy₂PCH₂CH₂N(CH₂)₃ ⁺F as a white crystalline solid.

[0064] RuCl₂(═CHPh)(PPh₃)₂ (1.20 g, 1.53 mmol) prepared as above wasthen placed in a Schlenk flask equipped with a stirbar, capped with arubber septum, and purged with argon. CH₂Cl₂ (15.0 ml) was added, andthe dark green solution was cooled to −78° C. Cy₂PCH₂CH₂N(CH₂)₃ ⁺I (1.0g., 3.13 mmol, 2.05 equiv) was dissolved in methanol (10 mL) underargon, cooled to 78° C., and slowly added to the Schlenk flask viasyringe. The reaction mixture was stirred at −78° C. for 30 min while acolor change to dark red was observed. Stirring was continued for 30 minas the reaction warmed to room temperature. Removal of the solvent invacuo yielded a dark purple solid. The solid material was dissolved inCH₂Cl₂ (10 mL) and stirred, and pentane (100 mL) was added toprecipitate a purple solid. The brownish red supernatant was removed anddiscarded via cannula filtration, and this procedure was repeated untilthe supernatant became colorless. By this stage, the solid product wasinsoluble in CH₂Cl₂ and was further treated with heat CH₂Cl₂, until thewashings became colorless. The product was dissolved in methanol (15 mL)and cannula filtered from an insoluble dark purple material, and solventwas removed in vacuo to yield the desired productRuCl₂(═CHPh)[Cy₂PCH₂CH₂N(CH₃)₃ ⁺Cl]₂ as a purple solid (0.680 g, 67.4%).Although the [M⁺] peak was not observed in the FAB mass spectrum, theobserved isotopic abundance for corresponding [M+H−Cl⁻] peaksidentically matched the predicted isotope pattern for the [M+H−Cl⁻]fragment of RuCl₂(═CHPh)[Cy₂PCH₂CH₂N(CH₃)₃ ⁺Cl]₂.

[0065] Synthesis of RuCl₂(=CHPh)[Cy₂P(N,N-dimethylpiperidiniumchloride)]₂

[0066] RuCl₂(=CHPh)[Cy₂P(N,N-dimethylpiperidinium chloride)]₂ wasprepared as follows. Lithiation of Cy₂PH(BH)₃ with n-butylithium (10.0mL of a 1.6 M solution in hexane, 16.0 mmol. 1.06 equiv) was performedas described above. Upon cooling of the solution to −78DC, 6 (2.0 g.7.42 mmol. 0.5 equiv) in THF (50 mL) was slowly added via syringe. Thereaction mixture was maintained at −78° C. for 2 h and then stirred at60° C. for 6 h. Upon evaporation of the solvent ether (50 mL) andsaturated aqueous sodium bicarbonate solution (50 mL) were added. Theorganic phase was separated and the aqueous phase extracted with ether(2×100 mL). Evaporation of the combined organic layers gave a whitesolid which was subjected to column chromatography (silica gel/methanol,R₁=0.22) to yield 1.25 g (54%) of a white solid. This solid was thenmethylated with methyl iodide, analogous to method described above forthe methylation of Cy₂PCH₂CH₂N(CH₂)₃ ⁺I to yieldCy₂P(BH₃)(N,N-dimethylpiperidinium iodide) as a white solid (98%), whichwas then converted with morpholine to yieldCy₂P(N,N-dimethylpiperidinium iodide) as a white solid (73%), again by amethod analogous to that described above for the conversion ofCy₂PCH₂CH₂N(CH₂)₃ ⁺I to Cy₂PCH₂CH₂N(CH₂)₃ ⁺I.

[0067] RuCl₂(PPh₃)₃ (1.38 g, 1.44 mmol) prepared as above was placed ina Schlenk flask and purged with argon. CH₂Cl₂ (15.0 mL) was added, andthe dark red solution was cooled to −78° C. Phenyldiazomethane (0.340 g,2.88 mmol, 2.0 equiv) was quickly weighed under air, dissolved inpentane (1.0 mL), cooled to −78° C., and added to the Schlenk flask viapipet under an argon purge. Upon addition of the diazo compound, aninstantaneous color change from dark red to dark green was observed. Thereaction was stirred for 5 min. and a solution ofCy₂P(N,N-dimethylpiperidinium iodide) (1.10 g, 3.18 mmol, 2.2 equiv) inmethanol (10 mL) was added via syringe. The solution became dark-red,and stirring was continued for 30 min as the reaction warmed to roomtemperature. Solvent was removed in vacuo and dried overnight to yield aburgundy solid. The solid material was dissolved in CH₂Cl₂ (15 mL) andstirred, and pentane (100 mL) was added to precipitate a burgundy solid.Pentane should be added quickly, as 19 slowly decomposes in CH₂Cl₂. Thedark red supernatant was removed and discarded via cannula filtration,and the product was reprecipitated until the supernatant was colorless.The solid was dissolved in CH₂Cl₂ (10 mL), precipitated by addition ofthe THF (150 mL) and cannula filtered. This process continued until thesupernatant was colorless. The product was dissolved in methanol (10 mL)and cannula filtered from insoluble material, and solvent was removed invacuo to yield the desired RuCl₂(=CHPh)[Cy₂P(N,N-dimethylpiperidiniumchloride)]₂ product as a burgundy solid.

EXAMPLE 2

[0068] Synthesis of Olefin Monomers

[0069] Synthesis ofexo-N-(N′,N′,N′-trimethylammonio)ethyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximidechloride. Exo-bicyclo[2.2.1 ]hept-5-ene-2,3-dicarboxylic anhydride(2.03g, 12.37 mmol) and N,N-dimethylethylenediamine (1.09g, 12.37 mmol)were dissolved in CH₂Cl₂ (30 mL) and heated at 90° C. for 8 hours in aheavy-walled sealed tube. Upon cooling to room temperature, thissolution was washed with brine (3×), the organic layer was dried oversodium sulfate, and the solvent was removed in vacuo. This whitecrystalline product was dissolved in THF (20 mL) and subsequentlytreated with 5 equivalents of methyl iodide at room temperature. Theresulting white precipitate was filtered, washed liberally with THF, anddried under vacuum to yield the title compound as an iodide salt.Iodide/chloride ion exchange as previously described³ afforded 3 as awhite flaky solid (34% yield based on anhydride starting material). ¹HNMR δ (CD₃OD): 6.38 (s, 2H), 4.0 (t, J=7.05 Hz, 2H), 3.54 (t, J=7.2 Hz,2H), 3.25 (s, 2H), 3.22 (s, 9H), 2.90 (s, 2H), 1.37 (dd, J=9.9 Hz, J=9.9Hz, 2H). ₁₃C NMR δ (CD₃OD): 177.53, 137.26, 61.86, 52.29, 47.54, 44.73,42.07, 31.60.

[0070] Synthesis ofexo-N-(N′,N′,N′-trimethylammonio)ethyl-bicyclo-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboximidechloride.

[0071] In a three-necked round bottom flask under an atmosphere ofnitrogen, exo-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride(4.0g, 24.07 mmol) and N,N-dimethylethylenediamine (3.17 g, 35.98 mmol)were dissolved in toluene (40 mL). Magnesium sulfate (8.0 g) was addedto this solution and the reaction was heated at 60° C. for 23 hours.Upon cooling to room temperature, the reaction mixture was filtered andwashed with water (4×). The organic layer was dried over sodium sulfateand the solvent was removed in vacuo. This white crystalline product wasdissolved in THF (15 mL) and subsequently treated with 2.1 equivalentsof methyl iodide at room temperature. The resulting white precipitatewas filtered, washed liberally with THF, and dried under vacuum to yieldthe title compound as an iodide salt. Iodide/chloride exchange aspreviously described³ afforded 4 as a white flaky solid (14% yield basedon anhydride starting material). ¹H NMR δ (CD₃OD): 6.56 (s, 2H), 5.19(s, 2H), 3.94 (t, J=6.0 Hz, 2H), 3.58 (t, J=6.44 Hz, 2H), 3.18 (s, 9H),3.00 (s, 2H). 13C NMR δ (CD₃0D): 176.58, 136.34, 81.03, 62.28, 52.59,52.50, 32.49.

EXAMPLE 3

[0072] Acid activation of ROMP of DCPD

[0073] Ruthenium catalysts 1-5 prepared as in Example I show enhancedactivities for the ROMP of high- and low-strained cyclic olefins, theRCM and ADMET of multiply-unsaturated substrates, and the acyclic crossmetathesis of linear olefins in the presence of acids.

[0074] Typical polymerization reactions were conducted in the followingmanner. In a nitrogen-filled drybox, monomer was added to a NMR tube ora vial equipped with a teflon-coated stirbar and capped with a rubberseptum. The ruthenium alkylidene catalysts were added to a second vialand the vial was capped with a rubber septum. Outside the drybox, wateror methanol was added to each vial via syringe, and the polymerizationwas initiated by transferring the catalyst solution to the vialcontaining the monomer.

[0075] The addition of acid to ruthenium catalysts 1-5 results in fastercatalyst turnover and increased yields for reactions with olefins thatare otherwise slow, incomplete, or not reactive. This enhanced activityis observed in both protic solvents such as water or methanol (withcomplexes 3-5) and organic solvents (with complexes 1-4) with eitherstoichiometric or nonstoichiometric equivalents of strong or weakorganic and inorganic acids. Acids may be added to the catalysts eitherbefore or during the reaction with olefin, with longer catalyst lifeobserved when the catalyst is introduced to an acidic solution of olefinmonomer. This allows the metathesis of a wider range of olefins in abroader range of solvents than previously possible. Comparative resultsof ROMP reactions using complexes 3 and 4 with different monomers, inneat monomer or methanol, and in the presence and absence of HCl aretabulated in Table 1 below. TABLE 1 Acid Yield Complex Monomer (HCl)Solvent Temp Time (%) 3 DCPD no none RT days 0 3 DCPD yes none RT <1 min100 3 10 no MeOH RT days 0 3 10 yes MeOH RT 15 min 100 4 DCPD no none RTdays 0 4 DCPD yes none RT <1 min 100 4 10 no MeOH RT 12 h 100 4 10 yesMeOH RT 15 min 100 DCPD = dicyclopentadiene; monomer 10 =

[0076] As seen from Table 1, complex 3 does not react at all witholefins in the absence of acid, and complex 4 reacts extremely slowly inthe absence of acid. Upon addition of acid, reactions occur to 100%yield within minutes. Thus, complexes 3 and 4 can be stored in solutionin the presence of olefin without reaction, and acid can be added asdesired to initiate catalysis in a RIM-type process with strained,cyclic olefins such as dicyclopentadiene (DCPD). Additionally, UV curingof DCPD to yield poly(DCPD) by photoinitiated-ROMP (PROMP) is readilyaccomplished as photoacid generators may be stored with both monomer andcatalyst until metathesis is initiated through irradiation.

EXAMPLE 4

[0077] Acid Activation in RIM Processes

[0078] Catalysts 1 and 2 of Example 3 are efficient catalysts for thebulk polymerization of both endo- and exo-dicyclopentadiene (DCPD),yielding a hard, highly-crosslinked material.

[0079] These catalysts are active enough, however, that polymerizationensues shortly after monomer and catalysts are mixed. On industrialscales, this can result in complete polymerization prior to injection ofthe reaction mixture into a mold. Catalysts 3 and 4 of Example 3,however, are unreactive toward DCPD in the absence, and can be storedindefinitely as a solution in DCPD monomer without appreciabledecomposition of the catalyst or polymerization of the monomer:

[0080] Upon addition of a strong inorganic acid or organic acid(particularly HCl) either as a gas, solid, or in a solution of water ororganic solvent, these catalysts are activated, and polymerizationensues immediately.

[0081] Thus, catalysts 3 and 4 can be stored with monomer, and be usedin reaction-injection molding (RIM) processes through combination withanother stream of monomer containing acid:

[0082] In addition, solutions of 3 or 4, monomer, and a photoacidgenerator can be stored together and used in photomasking applicationsthrough UV curing techniques.

EXAMPLE 5

[0083] Acid Activation of ROMP of Norbornenes

[0084] Acids can be used effectively to initiate the ROMP of othermonomers with these catalysts in solution as well. For example, whilesolutions of functionalized norbomenes and 7-oxanorbomenes do notpolymerize in the presence of catalysts 3 of Example 3, polymerizationrapidly ensues upon addition of from 0.3 or more equivalents of acid.Such monomers will polymerize using catalysts 4 of Example 3, althoughinitiation is very poor(<5%), even at elevated temperatures. In thepresence of acid, however, these catalysts fully initiate, and reactionsproceed to completion:

[0085] The results of the above reactions using catalysts 3 or 4 topolymerize monomer in the presence or absence of HCl and with methanolas a solvent are shown in Table 2 below. TABLE 2 Acid Yield ComplexMonomer (HCl) Solvent Temp Time (%) 3 10 no MeOH RT days  0 3 10 yesMeOH RT 15 min 100 4 10 no MeOH RT 12 h 100 4 10 yes MeOH RT 15 min 100

[0086] Again, complex 3 does not react at all with the olefin in theabsence of acid, and complex 4 reacts extremely slowly in the absence ofacid. Upon addition of acid, reactions occur to 100% yield withinminutes.

[0087] In addition, water-soluble catalyst 5 of Example 3 will alsopolymerize water-soluble norbornene and 7-oxanorbornene monomers inwater and methanol, but the catalyst typically dies at low conversion.Addition of up to one equivalent of HO or DO to these reactions resultsin complete conversion of monomer and the rate of polymerization isdoubled.

EXAMPLE 6

[0088] Acid Activation for Living ROMP in Water

[0089] In this example, activation in water with a strong Brønsted acidof alkylidene complexes RuCl₂(═CHPh)[Cy₂P(N,N-dimethylpiperidiniumchloride)]₂ (complex 6 below) and RuCl₂(═CHPh)[Cy₂PCH₂CH₂N(CH₃)₃ ⁻Cl]₂(complex 7 below) (prepared as in Example 1) results in the quantitativeconversion of functionalized monomers. In the presence of a Brønstedacid, complexes 6 and 7 quickly and quantitatively initiate the livingpolymerization

[0090] of water-soluble monomers in the absence of surfactant or organicsolvents.

[0091] This result is a significant improvement over aqueous ROMPsystems using “classical” aqueous ROMP catalysts. The propagatingspecies in these reactions is stable, and the synthesis of water-solubleblock copolymers was achieved via sequential monomer addition. Notably,the polymerizations are not living in the absence of acid. The effect ofthe acid in these systems appears to be twofold—in addition toeliminating hydroxide ions, which would cause catalyst decomposition;catalyst activity is also enhanced by protonation of phosphine ligands.Remarkably, the acids do not react with the ruthenium alkylidene bond.

[0092] Although alkylidenes 6 and 7 initiate the ROMP of functionalizednorbornenes and 7-oxanorbornenes in aqueous solution quickly andcompletely (in the absence of acid), the propagating species in thesereactions often decompose before polymerization is complete. Forexample, in the ROMP of water-soluble monomersexo-N-(N′,N′,N′-trimethylammonio)ethyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide chloride (monomer 13) andexo-N-(N′,N′,N′-trimethylammonio)ethyl-bicyclo-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboximide chloride (monomer 14) (prepared as inExample 2 above) initiated by alkylidene 6, conversions ranging from45-80% are usually observed (Equation 1). Although these water-solublecomplexes are similar to ruthenium alkylidenes which are very stabletoward polar and protic functional groups in organic solvents, theyappear to be susceptible to termination reactions when dissolved inwater or methanol.

[0093] The results of the above reactions with catalysts 6 and 7, in thepresence and absence of HCl is set forth in Table 3 below. TABLE 3 AcidYield Complex Monomer (HCl) Solvent Temp Time (%) 6 and 7 13 no H₂O 45 2h  45 6 and 7 13 yes H₂O 45 15 min 100 6 and 7 14 no H₂O 45 2 h  80 6and 7 14 yes H₂O 45 15 m 100

EXAMPLE 7

[0094] Acid Generation of New Monophosphine Alkylidene in Livng ROMPSystem

[0095] Consistent with data obtained for earlier “classical” aqueousROMP systems, we determined that the presence of hydroxide ions inaqueous solutions of catalysts 6 and 7 of Example 8 resulted in rapiddecomposition of the catalysts. In order to eliminate hydroxide ionsthat might result from the autoprotolysis of water or the basic natureof the phosphines employed, Bronsted acids were added to aqueouspolymerization mixtures of monomers 13and 14, catalysts 6 and 7, andwater. Although reactions performed in mildly acidic solutions ofDC1I/D₂O yielded no dramatic improvements, the monomers could becompletely polymerized in cases where 0.3-1.0 equivalent of DCl(relative to alkylidene) was added. The presence of acid also had aprofound effect on the reaction rate: the polymerizations were at leasttwice as fast as those to which no acid was added. More interestingly, apropagating alkylidene species was clearly observed by ¹H NMR followingcomplete consumption of monomer and addition of more monomer to thereaction mixture resulted in further quantitative polymerization.

[0096] To further investigate this effect, the reaction of DCl with 6was studied in the absence of olefin. Upon addition of 0.3 equivalentsof DCI to a D₂O solution of 6, the acid cleanly protonated 0.3equivalents of phosphine to yield a phosphonium salt and 0.3 equivalentsof a new alkylidene species, instead of protonating the ruthenium-carbondouble bond (Equation 2). The remarkable stability of the alkylidenebond in the presence of this very strong acid highlights the toleranceof ruthenium-based metathesis catalysts of the present invention towardprotic functionalities.

[0097] The new alkylidene generated upon addition of acid has beenidentified by ¹H and ³¹P NMR spectroscopy as a monophosphine derivativeof 6 such as that shown in Equation 2. In aqueous reactions employing upto one equivalent of acid, the monophosphine species is remarkablystable, presumably stabilized through coordination of water. Addition ofexcess phosphine to the reaction mixture up to 1.5 hours after additionof acid reverses the equilibrium, reforming 6 with less than 5%detectable decomposition. Protonation of phosphine in this manner is notstoichiometric. For instance, the addition 1.0 equivalent of DO yieldedan equilibrium mixture of monophosphine and bisphosphine alkylidenespecies in a ratio of 1:2. The alkylidenes decomposed more rapidly underthese conditions in the absence of monomer.

[0098] As anticipated, we found that monomers 13 and 14 could becompletely polymerized when up to 1.0 equivalent of DO was added to thereaction mixture. Additionally, the presence of acid also had a profoundeffect on the reaction rate: the polymerizations were up to ten timesfaster than those to which no acid had been added. More significantly,two propagating alkylidene species were observed by ¹H NMR spectroscopyfollowing complete consumption of monomer, and the addition of moremonomer to the reaction mixture resulted in further quantitativepolymerization. The direct observation of propagating species isimportant, as it allows the extent of chain termination, a key factor indefining a living system, to be easily and directly addressed throughoutthe course of the reaction.

[0099] The alkylidenes observed in the above reactions, corresponding toboth bisphosphine and monophosphine propagating species, aresignificantly more stable than the respective initiating speciesoutlined above. In fact, at ambient temperature, the propagating speciesin these reactions can be observed for well over one month.

[0100] In addition to the relatively low concentration of themonophosphine species dictated by the equilibrium in Equation 2,stability toward bimolecular decomposition is presumably imparted viathe relative steric bulk of the propagating alkylidene. The ¹H NMRresonances for the two propagating alkylidenes coalesce at highertemperatures, indicating rapid equilibration via phosphine scrambling.

[0101] To probe the living nature of the aqueous polymerizationsconducted in the presence of acid, an NMR-scale polymerization ofmonomer 13 was conducted employing DCl (1.0 equivalent relative toalkylidene), and the relative amount of propagating species wasquantified via integration of the alkylidene protons against thearomatic protons of the polymer endgroups. After 15 minutes at 45° C.,the reaction was >95% complete and the relative integration of thealkylidene protons of the two propagating species (coalesced as a broadsinglet at 19.2 ppm) did not decrease either during the reaction orafter all monomer had been consumed. In fact, the propagating speciesremained intact for an additional 15 minutes in the absence of monomerbefore slowly decomposing.

[0102] A block copolymerization of monomers 13 and 14 was carried out,via sequential monomer addition, to demonstrate the robust nature of thepropagating species in these reactions. After complete polymerization ofmonomer 13, the reaction was allowed to sit for 5 minutes before 20equivalents of monomer 14 were injected. Monomer 14 was rapidly andcompletely consumed, and the concentration of the propagating speciesremained constant both during and after the polymerization of the secondblock.

[0103] Within the limits of NMR sensitivity, the direct observation andquantification of the propagating alkylidenes in the above experimentsdemonstrates the absence of chain termination in these reactions. Thefact that the alkylidene resonance does not disappear over a time periodtwice as long as the time scale of the reaction indicates that thesesystems are indeed living. Gel permeation chromatography (GPC) analysisof these polymers yields a symmetric, monomodal peak with apolydispersity index (PDI) of 1.2-1.5.

[0104] The equilibrium represented in Equation 2 provides astraightforward explanation for the rate enhancements, and thus theliving nature, of the polymerizations described above. For alkylidenecomplexes of the present invention of the type (PR₃)₂Cl₂Ru═CHR, olefinmetathesis has been shown to proceed through a mechanism in which aphosphine dissociates from the metal center. Rates of olefin metathesisin organic systems have been increased by the addition of phosphinescavengers, favoring the equilibrium for olefin coordination andphosphine dissociation, although the catalyst rapidly decomposes underthese conditions. In aqueous systems employing complexes 6 and 7,protons act as phosphine scavengers, increasing the rate of olefinmetathesis without concomitant acceleration of catalyst decomposition.The differences in the rates of propagation and termination under acidicconditions allows for rapid, quantitative conversion of monomer in aliving manner.

EXAMPLE 8

[0105] ROMP of Unstrained Cylic Olefins and Metathesis of AcyclicOlefins

[0106] In contrast to the “classical” ruthenium metathesis catalystsmentioned above, which react only with highly-strained olefins,alkylidenes 6 and 7 of Example 6 also promote the ROMP of less-strainedmonomers such as 1,5-cyclooctadiene, and are active in the metathesis ofacyclic olefins in protic solvents. For example, 6 will dimerize1-hexene in methanol to give 5-decene in 20% yield (Equation 3). Inthese systems, separation of catalyst from product is facilitatedthrough addition of water to the reaction mixture. Olefins collectedfrom the resulting two-phase system contain very low levels ofdetectable ruthenium.

[0107] Although the invention has been described in some respects withreference to the above embodiments, many variations and modificationswill be apparent to those skilled in the art. It is therefore theintention that the following summary not be given a restrictiveinterpretation, but rather should be viewed to encompass such variationsand modifications that may be routinely derived from the inventivesubject matter disclosed.

What is claimed is:
 1. A process for performing an olefin metathesis reaction comprising: contacting an olefin monomer with a ruthenium carbene complex of the formula: A_(x)L_(y)X_(z)Ru═CHR′ in the presence of inorganic or organic acid, wherein: x=0, 1 or 2; y=0,1 or 2; and z=1 or 2; and wherein: R′ is selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl and substituted aryl; L is any neutral electron donor; X is any anionic ligand; and A is a ligand having a covalent structure connecting a neutral electron donor and an anionic ligand.
 2. The process of claim 1 wherein said acid is selected from the group consisting of HI, HCl, HBr, H₂SO₄, H₃O ⁺, HNO₃, H₃PO₄, CH₃CO₂H and tosic acid.
 3. The process of claim 1 wherein said acid is HCl.
 4. The process of claim 1 wherein said acid is added to a solution comprising said olefin monomer and said ruthenium carbene complex.
 5. The process of claim 1 wherein said acid is generated by irradiating a photoacid generator.
 6. The process of claim 1 wherein the olefin metathesis reaction is conducted without a solvent.
 7. The process of claim 1 wherein the olefin metathesis reaction is conducted in a solvent selected from the group consisting of protic solvents, aqueous solvents, organic solvents and mixtures thereof.
 8. The process of claim 7 wherein the process is conducted in a solvent selected from the group consisting of aromatic solvents, halogenated aromatic solvents, aliphatic organic solvents, halogenated aliphatic organic solvents, alcoholic solvents, water and mixtures thereof.
 9. The process of claim 8 wherein said solvent is selected from the group consisting of benzene, dichloromethane and methanol.
 10. The process of claim 1 wherein L is a phosphine of the formula PR³R⁴R⁵, wherein R³ is selected from the group consisting of secondary alkyl and cycloalkyl, and R⁴ and R⁵ are each independently selected from the group consisting of aryl, C₁-C₁₀ primary alkyl, secondary alkyl, and cycloalkyl.
 11. The process of claim 10 wherein L is selected from the group consisting of —P(cyclohexyl)₃, —P(cyclopentyl)₃, —P(isopropyl)₃, and —P(phenyl)₃.
 12. The process of claim 1 wherein X is selected from the group consisting of hydrogen, halogen, and substituted or unsubstituted C₁-C₂₀ alkyl, aryl, C₁-C₂₀ alkoxide, aryloxide, C₃-C₂₀ alkyldiketonate, aryldiketonate, C₁-C₂₀ carboxylate, arylsulfonate, C₁-C₂₀ alkylsulfonate, C₁-C₂₀ alkylthio, C₁-C₂₀ alkylsulfonyl, and C₁-C₂₀ alkylsulfinyl, wherein substituents are selected from a group consisting of C₁-C₅ alkyl, halogen, C₁-C₅ alkoxy, phenyl, halogen substituted phenyl, C₁-C₅ alkyl substituted phenyl, and C₁-C₅ alkoxy substituted phenyl.
 13. The process of claim 1 wherein said ruthenium carbene complex is of the formula: A₂LRU═CHR′.
 14. The process of claim 13 wherein L is a phosphine of the formula PR³R⁴R⁵, wherein R³ is selected from the group consisting of secondary alkyl and cycloalkyl, and R⁴ and R⁵ are each independently selected from the group consisting of aryl, C₁-C₁₀ primary alkyl, secondary alkyl, and cycloalkyl.
 15. The process of claim 13 wherein L is selected from the group consisting of P(cyclohexyl)₃, P(cyclopentyl)₃, P(isopropyl)₃, and P(phenyl)₃.
 16. The process of claim 13 wherein said ruthenium carbene complex is of the formula:

wherein each R is independently selected from the group consisting of alkyl, substituted alkyl, aryl or substituted aryl.
 17. The process of claim 16 wherein each R is independently selected from the group consisting of (a) C¹-C₂₀ alkyl; (b) aryl; (c) C₁-C₂₀ alkyl substituted with one or more groups selected from the group consisting of aryl, halide, hydroxy, C₁-C₂₀ alkoxy, and C₂-C₂₀ alkoxycarbonyl; and (d) aryl substituted with one or more groups selected from the group consisting of C₁-C₂₀ alkyl, aryl, hydroxyl, C₁-C₅ alkoxy, amino, nitro, halide and methoxy.
 18. The process of claim 16 wherein R is methyl or t-butyl, PR₃ is P(cyclohexyl)₃, and R′ is phenyl
 19. The process of claim 1 wherein said ruthenium carbene complex is of the formula: ALXRu═CHR′.
 20. The process of claim 19 wherein L is a phosphine of the formula PR³R⁴R⁵, wherein R³ is selected from the group consisting of secondary alkyl and cycloalkyl, and R₁ and R⁵ are each independently selected from the group consisting of aryl C₁-C₁₀ primary alkyl, secondary alkyl, and cycloalkyl.
 21. The process of claim 19 wherein L is selected from the group consisting of P(cyclohexyl)₃, P(cyclopentyl)₃, P(isopropyl)₃, and P(phenyl)₃.
 22. The process of claim 19 wherein X is selected from the group consisting of hydrogen, halogen, and substituted or unsubstituted C₁-C₂₀ alkyl, aryl, C₁-C₂₀ alkoxide, aryloxide, C₃-C₂₀ alkyldiketonate, aryldiketonate, C₁-C₂₀ carboxylate, arylsulfonate, C₁-C₂₀ alkylsulfonate, C₁-C₂₀ alkylthio, C₁-C₂₀ alkylsulfonyl, and C₁-C₂₀ alkylsulfinyl, wherein substituents are selected from a group consisting of C₁-C₅ alkyl, halogen, C₁-C₅ alkoxy, phenyl, halogen substituted phenyl, C₁-C₅ alkyl substituted phenyl, and C₁-C₅ alkoxy substituted phenyl.
 23. The process of claim 19 wherein said ruthenium carbene complex is of the formula:

wherein each R is independently selected from the group consisting of alkyl, substituted alkyl, aryl and substituted aryl; R″ is selected from the group consisting of hydrogen, halo, nitro, and alkoxy; and X is selected from the group consisting of Cl, Br, I, CH₃CO₂ and CF₃CO₂.
 24. The process of claim 23 wherein R is selected from the group consisting of (a) C₁-C₂₀ alkyl; (b) aryl; (c) C₁-C₂₀ alkyl substituted with one or more groups selected from the group consisting of aryl, halide, hydroxy, C₁-C₂₀ alkoxy, and C₂-C₂₀ alkoxycarbonyl; and (d) aryl substituted with one or more groups selected from the group consisting of C₁-C₂₀ alkyl, aryl, hydroxyl, C₁-C₅ alkoxy, amino, nitro, halide and methoxy.
 25. The process of claim 23 wherein R′ is phenyl, R″ is nitro PR₃ is P(cyclohexyl)₃, X is Cl, and R is unsubstituted aryl or aryl substituted with a 2,6-diisopropyl group.
 26. The process of claim 1 wherein said ruthenium carbene complex is of the formula: L₂X₂RuαCHR′.
 27. The process of claim 26 wherein L is a phosphine of the formula PR³R⁴R⁵, wherein R³ is selected from the group consisting of secondary alkyl and cycloalkyl, and R⁴ and R⁵ are each independently selected from the group consisting of aryl, C₁-C₁₀ primary alkyl, secondary alkyl, and cycloalkyl.
 28. The process of claim 26 wherein L is selected from the group consisting of P(cyclohexyl)₃, P(cyclopentyl)₃, P(isopropyl)₃, and P(phenyl)₃.
 29. The process of claim 26 wherein X is selected from the group consisting of hydrogen, halogen, and substituted or unsubstituted C₁-C₂₀ alkyl, aryl, C₁-C₂₀ alkoxide, aryloxide, C₃-C₂₀ alkyldiketonate, aryldiketonate, C₁-C₂₀ carboxylate, arylsulfonate, C₁-C₂₀ alkylsulfonate, C₁-C₂₀ alkylthio, C₁-C₂₀ alkylsulfonyl, and C₁-C₂₀ alkylsulfinyl wherein substituents are selected from a group consisting of C₁-C₅ alkyl, halogen, C₁-C₅ alkoxy, unmodified phenyl, halogen substituted phenyl, C₁-C₅ alkyl substituted phenyl, and C₁-C₅ alkoxy substituted phenyl.
 30. The process of claim 26 wherein said ruthenium carbene complex is of the formula:

wherein PR₃ is selected from the group consisting of P(cyclohexyl)₃, P(cyclopentyl)₃, P(isopropyl)₃, and P(phenyl)₃ and wherein X is selected from the group consisting of Cl, Br, I, CH₃CO₂ and CF₃CO₂.
 31. The process of claim 26 wherein said ruthenium carbene complex is of the formula:

and wherein Cy is cyclohexyl and R is independently selected from the group

consisting of: and wherein X is selected from the group consisting of Cl, Br, I, CH₃CO₂ and CF₃CO₂, and wherein the olefin metathesis reaction is conducted in an aqueous or alcoholic solvent or mixtures thereof.
 32. The process of claim 31 wherein the ruthenium carbene complex is:

and wherein the olefin metathesis reaction is conducted in an aqueous or alcoholic solvent or mixtures thereof.
 33. The process of claim 31 wherein the ruthenium carbene complex is:

and wherein the olefin metathesis reaction is conducted in an aqueous or alcoholic solvent or mixtures thereof.
 34. The process of claim 1 wherein said olefin metathesis reaction is selected from the group consisting of ring opening metathesis polymerization, ring closing metathesis, acyclic diene metathesis, and cross metathesis.
 35. The process of claim 1 wherein said olefin monomer is selected from the group consisting of strained cyclic olefins, unstrained cyclic olefins, acyclic olefins, dienes, and unsaturated polymers.
 36. The process of claim 35 wherein said olefin monomer contains a functional group selected from the group consisting of alcohol, thiol, ketone, aldehyde, ester, disulfide, carbonate, imine, carboxyl, amine, amide, nitro acid, carboxylic acid, isocyanate, carbodiimide, ether, halogen, quaternary amine, carbohydrate, phosphate, sulfate and sulfonate.
 37. The process of claim 1 wherein said reaction is ring-opening metathesis polymerization and said olefin monomer is a cyclic olefin.
 38. The process of claim 37 wherein said cyclic olefin contains a functional group selected from the group consisting of alcohol, thiol, ketone, aldehyde, ester, disulfide, carbonate, imine, carboxyl, amine, amide, nitro acid, carboxylic acid, isocyanate, carbodiimide, ether, halogen, quaternary amine, carbohydrate, phosphate, sulfate and sulfonate.
 39. The process of claim 38 wherein block copolymers are synthesized by sequential addition of a first cyclic olefin followed by the addition of a second cyclic olefin.
 40. The process of claim 37 wherein (1) the acid is dissolved in a first solution containing said cyclic olefin monomer, (2) the ruthenium carbene complex is dissolved in a second solution containing said cyclic olefin monomer, and (3) then said first solution is added to a said second solution.
 41. The process of claim 40 wherein said first and second solutions comprise neat olefin monomer.
 42. The process of claim 40 wherein said first and second solutions comprise water.
 43. The process of claim 37 wherein said cyclic olefin is selected from the group consisting of cyclobutene, cycloheptene, cyclooctene, cyclononene, cyclodecene, cyclooctadiene, cyclononadiene, cyclopentadiene and dicyclopentadiene and derivatives thereof.
 44. The process of claim 43 wherein said cyclic olefin contains a functional group selected from the group consisting of alcohol, thiol, ketone, aldehyde, ester, disulfide, carbonate, imine, carboxyl, amine, amide, nitro acid, carboxylic acid, isocyanate, carbodiimide, ether, halogen, quaternary amine, carbohydrate, phosphate, sulfate and sulfonate.
 45. The process of claim 37 wherein said cyclic olefin is selected from the group consisting of functionalized norbomenes and 7-oxanorbornenes.
 46. The process of claim 37 wherein said cyclic olefin is selected from the group consisting of endo-dicyclopentadiene and exo-dicyclopentadiene.
 47. The process of claim 1 wherein said olefin metathesis reaction is ring-closing metathesis and said olefin monomer is an acyclic diene.
 48. The process of claim 47 wherein said acyclic diene contains a functional group selected from the group consisting of alcohol, thiol, ketone, aldehyde, ester, disulfide, carbonate, imine, carboxyl, amine, amide, nitro acid, carboxylic acid, isocyanate, carbodiimide, ether, halogen, quaternary amine, carbohydrate, phosphate, sulfate and sulfonate.
 49. The process of claim 1 wherein said olefin metathesis reaction is acyclic diene metathesis or cross metathesis.
 50. The process of claim 49 wherein said olefin monomer contains a functional group selected from the group consisting of alcohol, thiol, ketone, aldehyde, ester, disulfide, carbonate, imine, carboxyl, amine, amide, nitro acid, carboxylic acid, isocyanate, carbodiimide, ether, halogen, quaternary amine, carbohydrate, phosphate, sulfate and sulfonate.
 51. The process of claim 49 wherein said olefin monomer is 1-hexene.
 52. A process for performing a ring opening metathesis polymerization reaction comprising: contacting a cyclic olefin monomer with a ruthenium carbene complex of the formula:

in the presence of an inorganic or organic acid; wherein: R′ is selected from the group consisting of alkyl, substituted alkyl, aryl and substituted aryl; PR₃ is a phosphine of the formula PR³R⁴R⁵, wherein R³ is selected from the group consisting of secondary alkyl and cycloalkyl, an d R⁴and R⁵ are each independently selected from the group consisting of aryl, C₁-C₁₀ primary alkyl, secondary alkyl, and cycloalkyl; and each remaining R is independently selected from the group consisting of alkyl, substituted alkyl, aryl and substituted aryl.
 53. The process of claim 52 wherein: PR₃ is selected from the group consisting of P(cyclohexyl)₃, P(cyclopentyl)₃, P(isopropyl)3, and P(phenyl)₃; and each remaining R is independently selected from the group consisting of (a) C₁-C₂₀ alkyl; (b) aryl; (c) C₁-C₂₀ alkyl substituted with one or more groups selected from the group consisting of aryl, halide, hydroxy, C₁-C₂₀ alkoxy, and C₂-C₂₀ alkoxycarbonyl; and (e) aryl substituted with one or more groups selected from the group consisting of C₁-C₂₀ alkyl, aryl, hydroxyl, C₁-C₅ alkoxy, amino, nitro, halide and methoxy.
 54. The process of claim 52 wherein R′ is phenyl, PR₃ is P(cyclohexyl)₃, and R is methyl or t-butyl.
 55. The process of claim 52 wherein said acid is HCl.
 56. The process of claim 52 wherein said acid is added to a solution comprising said cyclic olefin monomer and said ruthenium carbene complex.
 57. The process of claim 52 wherein said acid is generated by irradiating a photoacid generator.
 58. The process of claim 52 wherein the ring opening metathesis polymerization reaction is conducted without a solvent.
 59. The process of claim 52 wherein the ring opening metathesis polymerization reaction is conducted in a solvent selected from the group consisting of protic solvents, aqueous solvents, organic solvents and mixtures thereof.
 60. The process of claim 52 wherein said cyclic olefin contains a functional group selected from the group consisting of alcohol, thiol, ketone, aldehyde, ester, disulfide, carbonate, imine, carboxyl, amine, amide, nitro acid, carboxylic acid, isocyanate, carbodiimide, ether, halogen, quaternary amine, carbohydrate, phosphate, sulfate and sulfonate.
 61. The process of claim 60 wherein block copolymers are synthesized by sequential addition of a first cylic olefin followed by the addition of a second cyclic olefin.
 62. The process of claim 52 wherein (1) the acid is dissolved in a first solution containing said cyclic olefin monomer, (2) the ruthenium carbene complex is dissolved in a second solution containing said cyclic olefin monomer, and (3) then said first solution is added to a said second solution.
 63. The process of claim 62 wherein said first and second solutions comprise neat olefin monomer.
 64. The process of claim 62 wherein said first and second solutions comprise water.
 65. The process of claim 52 wherein said cyclic olefin is selected from the group consisting of functionalized norbornenes and 7-oxanorbornenes.
 66. The process of claim 52 wherein said cyclic olefin is selected from the group consisting of endo-dicyclopentadiene and exo-dicyclopentadiene.
 67. A process for performing a ring opening metathesis polymerization reaction comprising: contacting a cyclic olefin monomer with a ruthenium carbene complex of the formula:

wherein: Cy is cyclohexyl, R is independently selected from the group consisting of:

and X is selected from the group consisting of Cl, Br, I, CH₃CO₂ and CF₃CO₂, and wherein the ring opening polymerization reaction is conducted in the presence of an inorganic or organic acid and in an aqueous or alcoholic solvent or mixtures thereof.
 68. The process of claim 67 wherein the ruthenium carbene complex is:


69. The process of claim 67 wherein the ruthenium carbene complex is:


70. The process of claim 67 wherein said solvent is aqueous and said cyclic olefin is water-soluble.
 71. The process of claim 67 wherein said acid is HCl.
 72. The process of claim 67 wherein said acid is added to a solution comprising said cyclic olefin monomer and said ruthenium carbene complex.
 73. The process of claim 67 wherein said cyclic olefin contains a functional group selected from the group consisting of alcohol, thiol, ketone, aldehyde, ester, disulfide, carbonate, imine, carboxyl, amine, amide, nitro acid, carboxylic acid, isocyanate, carbodiimide, ether, halogen, quaternary amine, carbohydrate, phosphate, sulfate and sulfonate.
 74. The process of claim 73 wherein block copolymers are synthesized by sequential addition of a first cylic olefin followed by the addition of a second cyclic olefin.
 75. The process of claim 67 wherein said cyclic olefin is selected from the group consisting of functionalized norbornenes and 7-oxanorbornenes. 